A 2846 will work for a 5500 case as far as I know. You could also try a 2452, or a 2472 to get a 18,000 bph rate. The date wheel will have to be removed, but there's not much to that.
I found the DSSD to be way too big. The Sea-Dweller is just right. The BPSD is a hell of a good watch with a little bit of work:
I added a gen crown , Clark's hands and a TC bracelet to mine.
I used a dremel to grind the cyclops down. You have to be careful not to take too much off, then I polished with silvo and a rag. This was prior to me acquiring green jewelers rouge, which is how I would recommend to it.